Strong Correlation between Anomalous Quasiparticle Scattering and Unconventional Superconductivity in Hidden Order Phase of URu$_2$Si$_2$

TL;DR

This study reveals a strong correlation between anomalous quasiparticle scattering and unconventional superconductivity in URu$_2$Si$_2$, showing deviations from Fermi liquid behavior in the hidden order phase and suggesting a universal mechanism near quantum criticality.

Contribution

It demonstrates a universal relation between quasiparticle scattering and superconductivity in the hidden order phase of URu$_2$Si$_2$, highlighting the role of strong correlations.

Findings

Deviations from Fermi liquid behavior in the HO phase.

Proportionality between scattering coefficient and superconducting temperature.

Strong correlation indicating a common origin for scattering and superconductivity.

Abstract

The pressure dependent electrical resistivity of URu$_2$Si$_2$ has been studied at high pressure across the first order phase boundary of $P_x$ where the ground state switches under pressure from "hidden order" (HO) to large moment antiferromagnetic (LAFM) states. The electrical transport in URu$_2$Si$_2$ at low temperatures shows a strong sample dependence. We have measured an ultra-clean single crystal whose quality is the highest among those used in previous studies. The generalized power law ${\rho}{\,}={\,}{\rho_0}+{\,}{A_n}T{^n}$ analysis finds that the electric transport property deviates from Fermi liquid theory in the HO phase but obeys the theory well above $P_x$. The analysis using the polynomial in $T$ expression ${\rho}{\,}={\,}{\rho_0}+{\,}{{\alpha}_1}T+{\,}{{\alpha}_2}T{^2}$ reveals the relation ${{\alpha}_1}/{{\alpha}_2}$ $\propto$ $T_{sc}$ in the HO phase. While the pressure dependence of ${{\alpha}_2}$ is very weak, ${{\alpha}_1}$ is roughly proportional to $T_{sc}$. This suggests a strong correlation between the anomalous quasiparticle scattering and the superconductivity and that both have a common origin. The present study clarifies a universality of the HO phase inherent in strongly correlated electron superconductors near quantum criticality.